Tractor-semitrailer coupling device



Jan. 26, 1954 J COLPQ 2,667,364

TRACTOR-SEMITRAILER COUPLING DEVICE Filed Feb. 23, 1952 2 Sheets-Sheet 1FIG. 1.

INVENTOR. JESSE CoL o @MM,M,MQ@M.

,4 TTORNEXY Jan. 26, I954 CQLPO 2,667,364

TRACTOR-SEMITRAILER COUPLING DEVICE Filed Feb. 23, 1952 2 Sheets-Sheet 2FIG. 4.

INVENTOR. d ESSE COLPO wwuau ATTORNEYS Patented Jan. 26, 1954 UNITEDSTATES PATENT OFFICE I 2,667,364 TRACTOR-SEMITRAILER OOUPLING DEVICEJesse Colpo, Orchard Park, N. Y. Application February 23, 1952, SerialNo. 273,069

16 Claims. 1

This invention relates generally to a connectlon device for supportingthe forward end of a trailing vehicle such as a trailer or asemi-trailer on the rear end of a vehicle such as a tractor, and morespecifically to such a connection device particularly adapted for usewith heavy duty carriers of the type commonly known as freighters. Thisapplication is a'continuation-in-part of applicant's copendingapplication Ser. No. 250,656, filed October 10, 1951, and entitledTractor Trailer Connection Device.

Many problems arise in providing suitable tractor-trailer connectiondevices. For example, if the connection device is such as to prevent anyrelative movement whatsoever between the tractor and the trailerlengthwise of the unit, sudden stops and starts impose a severe strainon the connection device. This is particularly dangerous if the'trailerbrakes do not function properly on a sudden stop, in which case theconnection device may fail completely and permit ,the trailer to crashinto the cab of the tractor. Another illustrative'problem is the nec-'essityf for providing adequate transverse support for the trailerwhereby to prevent tipping of thejjsame. Other problems, too' numerousto list here, are well known to those skilled in the art.

Accordingly, it is an object of this invention to provide a vehicleconnection device arranged to permit limited and controlled relativelengthwise movement between the vehicle and the trailing vehicle.

' Another object of this invention is to provide a tractor-trailerconnection device incorporating an improved shock absorbing arrangementoperative'upon-forward movement of the trailer relative to the tractor.:IIn addition, it is an object of this invention to provide a vehicleconnection device arranged to provide full transverse support for thetrailing vehicle at all times.

It is also an object of this invention to provide a vehicle connectiondevice in the nature of a fifth wheel structure which can be used withconventional trailing vehicle structures without modification thereof.

A further object of this invention is the provision of a tractor-trailerconnection device providing a support arrangement of improved stability.

Still another object of this invention resides in providing atractor-trailer connection device incorporating-cushioned stop meansautomatically preventing jackknifing of the tractor and trailer beyondapproximately 94 degrees.

An additional object of the instant inven tion is to provide a vehicleconnection device inmerals designate like parts throughout the variousviews and wherein:

Fig. l is a view in side elevation of a tractortrailer unit embodyingthe connection device of the instant invention;

Fig. 2 is a fragmentary perspective view of the connection device of theinstant invention;

Fig. 3 is a view in side elevation of the connection device of Fig. 2taken along line IIII1I of Fig. 4;

Fig. 4 is a plan view, with certain parts in section,of the connectiondevice of Fig. 2;

'Fig. 5 is a plan view of the fifth wheel element of the connectiondevice of the instant invention;

Fig. 6 is a plan view of a manually operable locking member utilizedinthe connection device of the instant invention; and

Fig. 7 is a view in sideelevation of the locking device of Fig. 6.

There is shown in Fig.1 of the .drawings'a tractor I and a trailer 2coupled thereto by the connection device of the instant invention.Tractor l is provided at'its rearward portion with side frame memberstand 4, and a floor member 5 extends between and overlies said framemembers and is secured thereto by means of U-bolts 6. The forward end oftrailer 2 is recessed, as at I, and said recess accommodates the rearwheels 8 0f tractor I together with the connection device of'theinstantinvention, the forward end of said trailer being connected to therearward portion of the tractor in a manner to be described. p v

The connection device of the instant invention is seen to comprise astabilizer or base plate H] mounted on floor 5 for rotary movementrelative thereto'about a substantially upright or vertical axis,beingsecured to said floor by means of a bolt ll. together with a nut l2and washer means I 3. Of course, base plate 10 and floor 5 areappropriately lubricated to permit substantially friction-free relativemovement therebetween.

Diametrically opposed spaced-apart bracket members l4 and I5 are formedon or secured to cluding means operable to hold or lock a tractor baseplate Ill, as by welding or the like, and have at their upper portionsbearing members 16 and 11, respectively, each of said bearing memberscomprising two parts secured together as by means of bolts [8, orthelike; A crankshaft I9 is removably journale'd in bearings l6 and I1, andextends therebeyond at its opposite ends. Crank arms 20 and2l arefixedly mounted on the outer ends of crankshaft l9 whereby to dependtherefrom and move therewith, and said crank arms carry at their lowerends outwardly directed shafts 22 and 23, respectively. Support armmem-' bers 24 and 25,, fixed tov depend from a plate 26 comprising afifth wheel structure, are pivotally connected at their lower ends ,toshafts Z2 and tailed description, taken together with the accom- 23, asclearly illustrated in Fig. 2, whereby support arms 24 and 25 and crankarms 20. and 2| together comprise a pair of articulated support members.

= at all times.

Fifth wheel plate 26 resembles in many respects portion havingrearwardly extending laterally spaced extensions 2'! inclined downwardlyshown in Fig. 3, with the space therebetween forming a forwardlyconvergig V-like slot merging into a relatively narrow slot 28 at.substan-eii tially the center of the circular portion Of said plate, asillustrated in Fig. 5. The upper surface of each of support members 24and 25 is shaped to form a fiat face portion, as at 29 and 29',respectively, and said face portions are secured to the underside ofplate 26 by any conventional means, as for example bolts 30, as clearlyshown in Fig, 3. A plate member 3|, having a substantially ilat undersurface, is rigidly secured to trailer 2 and a king pin 32 dependstherefrom, whereby in coupling together the trailer and the tractor,king pin 32 is received in slot 28, and plate 3| is thus carried onplate 26. The downwardly inclined extensions 21 facilitate in a knownmanner the coupling of trailer 2 to tractor I, permitting the forwardend of trailer 2 to ride upwardly on said extensions and onto plate 26.King pin 32 is locked within slot 28 by a conventional lockingarrangement carried by plate 28 and which may comprise, for example,pivoted iaw members 33 manually operable by means of a lever 34.

For reasons which will become clearly apparent, plate 26 is lockedagainst movement relative to trailer 2, with all relative movementoccurring between base plate and floor of tractor l. Plate 26 is lockedagainst movement relative to r iler 2 by an arrangement compri in p cguide brackets 35 carried by trailer 2 to depend therefrom and eachprovidedv with a cam surface 36' on its forward inner surface. Plate 26is provid d. wit outwardly diver i arms 31 havin ears 38 carried attheir o ter ends, and a brace memb r 3.9 ext nds therebetwe n. Wh thetractor-trailer unit is coupled together, ears 3B bear against brackets35 and cooperate therewith. and with king pin 3.2 to lock plate 26against o em nt relative to trailer 2. Also, when coup ing the tract rto the'trailer, and in the event that plate '26 and extensions 2,! arenot properly alin'ed with trailer '2 and king pin 32, ears 38v engagecam surfaces 36 of brackets 35 to aid in automatically alining saidfifth wheel plate and a d k g n- I will be n t r a i e i n of ies- 2 and4', that base plate It is of a diameter aproximately q al t w dth. f flor 5, and that brackets 14 and I5 are spaced apart a distance sufiicientso that'support. members 24 and 215 are approximately located at opposededge portions of base plate H]. In addition, plate 26 is locked totrailer 2 in a position such that crankshaft l9 extends, and supportarms 24 and 25 are alined, transversely of trailer 2. Thus, sincefifth-wheel plate 26 is locked against-movement relative to trailer 2,with relative movement for turning purposes occurring between plate l0and floor 5, a maximum of transverse support is prov ded f tr il r 2..nd such suppor is provided Thus, even when tractor I and trailer 2 arejackknifed at right angles to each other, crankshaft. l9 and the varioussupport structures remain alinedj transversely of trailer 2, and thusthere is provided for said trailer a maximum of transverse support evenduring extreme turning movements whereby to prevent. any tipping motionof trailer '2.

. Z ha ner sed eer ey ere gid conn ctionde Also, since crank arm andsupport "arm 24, and crank arm 2! and support arm 25, comprise in effecta pair of articulated support members, with support arms 24 and eachbeing eccentrically mounted onshaft l9 for oscillatory swingingmovements relative thereto in a substantially vertical plane, limitedand controlled relative lengthwise movement between tractor l andtrailer-2 ispermitted. Thus, upon sudden stopping of tractor I, trailer2 is permitted a limited forward movement relative to tractor l, withsupport arms 24 and 25 and crank arrns 20 andi'Zl swinging forwardly andupwardly about the substantially horizontal axis defined by crankshaft|9. This limited relative movement cushions the shock and strain whichwould result from sud: den stops if arigid connection device wereutilized, and the weight of the trailing vehicleserves to aid indampening and absorbing the forces causing support arms 24 and 25 toswing up- Y wardly. Similarly, upon sudden starting, sup-J port arms 24and 25 will tend to swing upwardly and rearwardly, and again the weightof trailer 2 will come into play thereby providing a shock absorbingeffect,

Additional shockabsorbing means are provided which means are operativeupon forward movement of trailer 2 relative to tractor l. Thus, asillustrated in Figs. 2, 3 and, 4, there are provided two shock absorbingmembers located on the forward half of plate lil, said memberscomprising cylinders 43 and 4'5 carried by brackets, 4| and ill securedto base plate It as by Welding or the like. Said cylinders are providedat one end with integral wall members, and at their opposite rearwardend with removable cap members 42 and 42' threadedly secured thereon,and rod members 43 and 43 extend through cylinders 40 and 40',respectively, being bent at their rearward end portions into alinementwith support arms 24' and 25, respectively. Shock pads 44 and 44', whichpads may be made of either rubber or metal ma terial, are carried bysaid rearward end portions of rods 43 and 43.", respectively, andprovide fiat face portions adapted. to abut support arms 24 and 25upon'f-orward swinging movement thereof, as illustrated in Fig. 3.

A compression spring, as illustrated at 45 in Fig. 4, extends betweenthe forward end of cylinders 4n and 40' and a washer member carried byrods 43 and 43, as shown at 46,, with the rearward movement of saidwasher members along said rods being limited by nut members 41 and 41'.Thus, upon forward winging movements of support arms 24 and 25, saidarms contact shock pads 44 and 44, as illustrated in Fig. 3, andcompress said compression springs, which latter absorb. the energy ofsuch forward movement and thereby provide an effective shock absorbingarrangement. The pro-loading of said compression springs, as well as thedistance of shock pads 44 and 44' from support arms 24 and 25, can beregulated by a, lock nut arrangement 48 and 48' threadedly engaging the,forward end of each of rods 43 and 43' and adapted to bear againsttheforward end wall of cylinders 40 and 40, respec-: tively. Thus, theshock absorbing members can be adjusted by varying the position of locknuts 48 and 48' on rods 43 and 43'.

Two important functions served by the shock absorbing members are asfollows. Firstly, in the event that the trailer brakes, which normallyare set tonfunc-tion a predetermined interval before the tractor brakes,do not operate properly, the

vice upon arsudden stop might cause the connection'to fail completelyand permit the trailer to crash into the cab of the tractor. However,with theconnection device of the instant invention permitting a limiteddegree of. relative for- Ward movement and providing the shock absorbingarrangement previouslydescribed, the shock absorbers receive the shockofsudden stopping and absorb the forces tending to drive the trailertoward and into the cab of the tractor. In addition, whereas withoutsuch shock absorbers there would be a tendency for the trailer tocamthefifthwheel plate 26 upwardly to'a substantially vertical position duringcoupling movement, thus making it necessary to jam the tractor under thetrailer producing severe strain on the connection device, by providingthe shock absorbers disclosed herein such upward oammin of the fifthwheel-plate is effectively limited to a degree permitting easy couplingof the'tractor to the trailer and avoiding any undue strain on theconnection device.

In addition, whereas according to the instant invention means includingbracket members 35 are provided for locking fifth wheel plate 26 againstmovement relative to trailer 2, with relative movement occurring betweenplate In and floor 5, the coupling device of the instant invention isadapted for use with conventional trailing vehicle structures adapted toreceive a conventional fifth wheel element but not modified to providebracket members corresponding to bracket members 35. Thus, when couplingto a trailer utilizing a king pin connection, a tractor provided withthe instant coupling or connection device need only back under thetrailer to cause fifth wheel plate 26 to receive the king pin in themanner heretofore described. However, in such case relative rotationbetween plate 26 and plate 3| would be permitted to occur. Thus,.uponturnin movements, rotation'might occur between the connection device andthe trailer, rather than between the connection device and the tractor,causing shaft l9 to be alined longitudinally of trailer 2, and, uponstraightening out the tractortrailer unit, it is possible that shaft I9, might remain alined longitudinally of trailer 2, thereby providingonly a very limiteddegree of transverse support. Accordingly, to permitthe connection device of the instant invention to be safely used withconventional trailer structures not modified to provide locking bracketmeans, means are provided for locking the connection device againstmovement relative to tractor l, whereby although during 'turningmovements shaft I9 will move out of transverse alinement with trailer 2,upon straightening out theunit full transverse support will once againbe provided.

Such means are illustrated in Figs. 2, 6 and '7, and are seen tocomprise a slidable locking bar 50 provided with a cam faced forward end5| adapted to be received in a complementary shaped notch or recess 52in the edge of plate 10, said locking bar and said recess being arrangedso that upon engagement thereof plate I is locked against movementrelative to floor and with support brackets l4 and I5 and crankshaft l9alined transversely of tractor I. Thus, full transverse support will beprovided as heretofore described whenever the tractor and trailer are inlongitudinal alinement, and will be restored after each turning movementof tractor I relative to trailer 2. Locking bar 50 is slidable withinspaced brackets 53 secured to floor 5 asby means of bolts 6 54 or thelike, andis provided with an supstanding wall plate 55 adapted to bearagainst the outer bracket 53 to limit rearward movement of bar 50. Ahandle member 56 is connected to plate 55 and extends through a secondplate 51 welded or otherwise secured to floor 5, and a compressionspring 58 extends between plates 55 and 51. Thus, spring 58normally'biases lockingbar 50 into engagement with recess 52, but uponpulling outwardly on handle member 56 said locking bar is disengagedfromsaid recess. Handle member 56 is provided with a hole 59extendingtherethrough, and when it is desired to retain bar-50 inunlocked position handle 56 is pulled outwardly and a pin, notillustrated, is dropped through hole 59 to bear against plate 51 andprevent handle 56 and consequently locking bar 50 from moving inwardlyunder the bias of spring 58. When it isdesire'd to engage said lockingbar with recess 52, it is only necessary to remove-the aforesaid pin andpermit spring 58 to cause such locking engagement. T

Of course; this locking arrangement is used only when a tractor providedwith a connection device of the instant invention is coupled'to atrailer which is not provided with lockingmeans preventing rotation ofthe fifth wheel plate relative to the trailer. Also, by reason of thecam shape of recess 52 and the forward end of looking bar 50, when saidlockingbar is released" for engagement with said recess, if it is notproperly alined therewith initially it will cam into engagementtherewith under the influence of spring 58 upon proper alinement. At thesam time, when said locking bar is engaged in said recess, if for anyreason some binding action should occur preventing relative rotationbetween fifth wheel plate 26 and-trailer 2, upon any attempted turningmovement producing excessive strain on the connection device the forcethus produced will overcome the bias of spring 58 and locking bar 50will automatically cam out of engagement with recess 52, therebypermitting suchturning movement. Thus, spring' 58 is properly selectedto overcome normal forces thereon but yield to excessive forces. I

The instant invention also provides stop means preventing jackknifing ofthetractor and trailer to more than approximately a 94 angle. Ifthetractor and trailer are turned at more than approximately 94 to eachother, with many constructions the trailer will abut the cab of thetractor and thus damage thesame. Such extreme jackknifing might occurupon loss of control over the tractor-trailer unit, and also duringbacking maneuvers when the operator is unable to see the position of thetrailer with respect to the cab. For example, and particularly in thecase'of cabs providing a bunk at the rear of the cab behind theoperator, in backing maneuvers the operator sometimes cannot see theposition of the trailer relative to the cab when the same is turning tohis right, and damage to the cab quite often results.

Such stop means 'are seen to comprise a stop member 60 pivoted to floor5 of tractor 'l 'by-a' pivot pin BI, and having its inner end taperingoutwardly as at 62. The outer end of stop mem-' ber 60 extendstransversely between two spaced" brackets63 and 64 carried'on floor 5,and spring members 65 and 66 extend between stop member 60 and brackets63 and 64, respectively. Said spring members are retained in position byretainers 61 on member 60 and retainers 68 on brackets 63 and, asillustrated, and may be connected to said brackets and said stop memberin any known manner whereby to prevent acci dental disassembly thereof.Said springs are of r l iv ly sh len th, and are relatively strong,acting as shock absorbing means permitting an approximately 5 cushionedpivoting movement of member Ell in either direction. The sides oftapered end 62 are designed to abut support arms 24 and 2.5 after aboutan-89 turn in either direction.

The inner end 62 of stop member 60 intersects the path of movement ofsupport arms 24 and 25, thus being operatively alined therewithwhereupon during turning movements, and as a e plate I rotate relativeto flo r '5. the sup-.- PQrt arm 24 or 25 thu caused to a proach stopmember 60 will abut the outer end 62 thereof upon approximately an 89turn, and will move thesame against the action of spring 65 or 66,whichever is the case, through a further 0! cushioned shock absorbingmovement until approximately a full 9d turn has been realized, at whichtime the appropriate spring 55 or 66 will have been so compressed thatmember 6!! acts as a positive stop against further relative rotationbetween tractor I and trailer 2. Thus, even though the operator of thetractor cannot see the position of the trailer, stop member 59 acts toprevent relative turning or jacklrnifing beyond about a 94 angle, andthereby prevents damage to the trailer and the cab of the tractor whichwould otherwise result.

The connection device of the instant invention also provides means forholding or looking the vehicle and trailing vehicle in any desiredrelative angular position. To this end, there is mounted on a bracket10, secured to floor 5 by welding or any other conventional means, ahollow cylinder ll containing therein a piston member 12 and a pistonrod 15 attached to said p ston member and a ryin at its oute e d a brakeshoe 14 having a curved surface conformi to the perip y of pl te 10 andp ov ded with anappropriate friction bralge surface 15. Springs 16 and11' extend between cylinder H and brackets 18 and I9, respectively,carried by floor 5, and serve as shock absorbing springs in much thesame manner as springs $5 and 66, although pivotal movement of cylinderU is not intended and said springs serve more of a safeguard purpose.Said sp i s 6 and H may be connected to cylinder H and brackets 18 and19 in any desired manner, and are retained position by retaining members30 carried by cylinder Hand members .81 carried by brackets 18 and 19, Aconduit 82 extends Irom cylinder (Land said cylinder m arranged in aconvene tional manner to operate under fluid pressure, either by theapplication of pressure or a vacuum thereto through conduit 82. all in aknown mann r,-

Thus, upon actuating cylinder H an piston 12 either automatically upon apredetermined turning movement or selectively at the will of: theoperator, brake shoe 14 will be caused to engage the rimof plate-l0 andhold or .1 91; the same against rotation relative to floor ,5. H desiredor necessary in any specific instance, the of plate [,0 can be enlargedto provide an upstanding rim presenting a greater surface area for thebraki g ac ion- T e importance of this brake means is obvious since if,for example, the

tra l r should e i t i ckk if upon the trac or in an undesirable manner.h operator can actua e pis on 12 o apply brake shoe 14 to plate l0. andhold or look the trailer against jurther jackkniiing action, thusenabling the operator to prevent the serious and sometimes disastrousconsequences which might otherwise occur.

Thus, it is seen that the instant invention fully accomplishes theaforesaid objects in providing an extremely stable tractor-trailerconnection device giving full transverse support to the trailer at alltimes and even during turning movements of. the tractor-relative to thetrailer. Addition-s ally, this connection device can be used withconventional trailer structures and means are provided to insure properoperation in such use. Also, the instant connection device provides ashock absorbing arrangement operative upon forward movement of thetrailer relative. to the tractor, together with stop means limiting thedegree of jackknifing possible between the tractor and the trailer andmeans for holding or locking the trailer to the tractor to preventrelative movement therebetween. While the instant in.- vention has beendisclosed in a preferred embodiment thereof, it is-to be understood thatthe same is not necessarily limited to the various details of suchembodiment, but can occupy other forms and modifications thereof withoutdeparting from the inventive concept. Accordingly, it is intended thatthis invention be defineda-nd limited solely by the scope of theappended claims.

Having completely disclosed and fully described the instant invention ina preferred embodiment thereof, together with its mode of operation,what is claimed as new is as follows:

1. In combination with a tractor and a trailer. a connection devicetherefor comprising base plate means supported on said tractor for move--ment relative thereto about a substantially vertical axis, spacedupstanding support members carried by saidbase plate means, shaft meansjournaled in saidsupport members, spaced support arms eccentricallypivoted to opposite ends of said shaft means for swinging movementthereabout in a substantially vertical plane, means connecting saidsupport arms to said trailer, and resilient shock absorbing means inoperative alinement with at least one of said support arms to limit andcushion the swinging movement thereof.

2. A connection device as set forth in claim 1, wherein said shockabsorbing means includes a spring biased shock pad together withadjusting means regulating the spring bias and position of said shockpad from said support arm.

8. A connection device as set forth in claim 1. wherein said shockabsorbing means comprises resilient shock absorbing members in operativealinement with each of said support arms and movable with said baseplate means.

4. In combination, a vehicle, a trailing vehicle, and a connectiondevice for coupling said trailing vehicle to said vehicle comprising,base plate means supported on said vehicle for movement relative theretoabout a substantially upright axis, spaced upstanding support bracketmeans carried by said base plate means, shaft means journaled in saidsupport bracket means to extend substantially horizontally therefrom,mounting plate means releasably connected to said trailing vehicle,spaced swinging articulated arm means extending between said mountingplate means and the opposite ends of said shaft means for supporting theformer on the latter, and resilient shock absorbing means operativelyalined with at least one of said articulated arm means to resilientlylimit the swinging movement thereof in one direction.

5. A connection device as set forth in claim 4, including means lockingsaid mounting plate means against movement relative to said trailingvehicle.

6. A connection device as set forth in claim 4, including locking meansfor holding said base plate means against movement relative to saidvehicle.

7. A connection device as set forth in claim 6, wherein said lockingmeans comprises a manually operable member selectively operable toengage recess means in said base plate means.

8. A connection device as set forth in claim 6, wherein said lockingmeans comprises fluid actuated brake means operable to frictionallyengage said base plate means.

9. In combination with a, vehicle and a trailing Vehicle, a connectiondevice therefor comprising, base plate means mounted on said vehicle formovement relative thereto in a substantially horizontal plane, shaftsupport means carried by said. base plate means, substantiallyhorizontally extending shaft means carried by said support means, linkmeans connected to said shaft means for swinging movements thereabout ina substantially vertical plane, means connecting said link means to saidtrailing vehicle, resilient shock absorbing means movable with said baseplate means and operatively alined with said link means to resilientlylimit the swinging movement thereof in at least one direction, and stopmeans operable upon predetermined movement of said base plate meansrelative to said vehicle to prevent furtlier relative movementtherebetween.

10. The combination set forth in claim 9, wherein said stop meanscomprises a springbacked pivoted member operatively alined with meanscarried by said base plate means to resiliently resist further relativemovement of said base plate means upon an approximately eightyninedegree relative turning movement between said vehicle and said trailingvehicle in either direction and positively prevent such further movementupon an approximately ninety-four degree turning movement therebetweenin either direction.

11. In combination with a vehicle and a trailing vehicle, a connectiondevice extending therebetween and comprising base plate means supportedon said vehicle for movement relative th reto about an axis, supportbracket means carried by said base plate means, shaft means journaled.in said bracket means, crank arm means carried by said shaft means, legmeans releasably connecting said trailing vehicle to said crank armmeans, and stop means carried by said vehicle and operatively alinedwith said leg means to prevent movement of said base plate meansrelative to said vehicle in either direction beyond a predeterminedpoint.

12. The combination set forth in claim 11, wherein said stop meanscomprises a pivotally mounted member spring backed in either direction.

13. In combination with a vehicle and a trailing vehicle, a connectiondevice therefor comprising a base structure carried by said vehicle andmovable relative thereto about an upright axis, shaft support meanscarried by said base structure, shaft means journaled in said shaftsupport means to extend substantially horizontally therefrom,articulated arm means mounted on said shaft means for swinging movementthereabout and supporting said trailing vehicle on said shaft means, andresilient shqck absorb- 10 ing means in operative alinement with saidarticulated arm means to cushion and limit the swinging movementthereof.

14. A tractor-trailer connection device comprising, a floor memberadapted to be mounted on a tractor, base plate means pivotally connectedto said floor member for rotation relative thereto, substantiallydiametrically opposed support brackets carried by said base plate means,shaft means journaled in said support brackets to extend substantiallyparallel to the plane of said base plate means, mounting plate meansadapted for connection to a trailer, spaced articulated arm meansconnecting said mounting plate means to said shaft means at spacedpoints thereon for swinging movement thereabout, and resilient shockabsorbing means carried by sai base plate means in alignment with atleast one of said arm means to cushion and limit the swinging movementthereof in a forward direction.

15. A tractor-trailer connection device comprising, in combination witha tractor, base plate means pivotally supported on said tractor formovement relative thereto about a substantially upright axis, spacedsupport brackets carried by said base plate means, shaft means journaledin said support brackets, mounting plate means adapted for connection toa trailing vehicle carried by said shaft means, means defining a camshaped recess in the periphery of said base plate means, a lockingleverslidably mountedon said tractonsaid lever having a cam shaped endportion engageable in said recess when aligned therewith and said spacedsupport brackets being aligned transversely of said tractor when saidrecess and said lever are aligned, spring means biasing said lever intoengagement with said recess, said spring means being designed to permitsaid lever to cam out of said recess automatically upon a predeterminedrelative turning force on said base plate means, and manually operablemeans for retracting said lever.

16. A tractor-trailer connection device comprising, in combination witha tractor, base plate means pivotally connected to said tractor forrotation relative thereto, mounting plate means adapted for connectionto a trailer, means supporting said mounting plate means on said baseplate means for rocking movement relative thereto, and stop meanslimiting the relative turning movement in either direction between saidbase plate means and said tractor, said stop means comprising a firstmember carried by said base plate means for movement therewith, and aspring backed second member pivotally connected to said tractor andextending into the path of said first member to intercept the same upona predetermined relative turning movement between said base plate meansand said tractor in either direction to first yieldingly oppose and thenpositively prevent further relative turning movement therebetween.

JESSE COLPO.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,100,463 Wohlfarth Nov. 30, 1937 2,130,004 Fusetti Sept. 13,1938 2,441,293 Seyferth May 11, 1948 2,499,013 Wood Feb. 28, 19502,567,312 Apgar Sept. 11, 1951

